Phosphorous oxychloride and ammonia reaction products in flame retarding compositions applied to cellulosic materials



atented Dec. 1, 19 53 EYES 'i'ET QFFICE Morris L. Nielsen, Dayton, Ohio, assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application June 21, 1950, Serial No. 169,507

7 Claims.

This invention relates to new compositions of matter and the manner of producing and applying them. The invention specifically relates to materials having utility in flame-retarding compositions with the particular objective of reducing the afterglow.

It is known that even widely used chemical compositions having utility in the reduction of flammability of fabrics and other combustible base materials fail to completely extinguish fire (for the reason that although flammability or after-flaming is reduced, the residual ash functions by catalytic action in the maintenance of an afterglow which persists for relatively long periods of time. Such afterglow may propagate itself through the base material so that a fire may again start at another point even when the flaming combustion has been extinguished.

It is an object of the invention to provide a composition of matter which may be combined 5 with or applied to otherwise combustible products to reduce the danger of afterglow.

In accordance with the terminology which has been adopted in this field, the term flame-retarding refers to the property of a material which is resistant to the propagation of flame across its surface after the igniting flame has been removed; that is, a properly treated material will not support combustion independently of an external source of flame. In contact with an open flame, however, or at elevated temperatures, treated, organic materials can be expected to char and decompose.

After-flaming refers to the persistence of a frame which continues to burn from the base material after he removal of the igniting flame. Afterglow refers to the persistence of a nonfiaming combustion. manifested as a red glow or incandescence which consumes the material after all flame has been extinguished.

In the problem of reducing the danger of fire in the use of various chemical treatments applied to cotton, rayon, wood and other combustible materials, it is obvious that the large proportions of carbon, hydrogen and oxygen, which are present in such cellulosic materials render these teriais particularly susceptible to combustion. Fr 1 art treatments intended to reduce the flamof such materials by means of tin oxide or antimony oxide formulations have been found to glow excessively after they have been in contact a flame. Such afterglow effects are particularly dangerous in fabric materials such as tentage, since such materials appear to have been extinguished and yet will maintain an afterglow ding throughout the treated material so that a fire may be propagated to other portions of the material. The glowing portions of the material may then contact other combustible materials and may set the fire into action again.

It is known that metallic oxides, such as antimony and titanium oxide, which have been utilized in some flame-proofing treatments, aid in promoting the catalytic eiiect which appears to occur in this afterglow phenomenon. In other words, a fiameless combustion may continue in such metallic oxide-treated material after the flame has been completely extinguished. Apparently, the metal oxides which are instrumental in bringing about the desirable suppression of flaming appear to be primarily responsi ble for the production of the undesirable afterglow.

The above phenomenon has been recognized and is discussed in an article entitled Trends in the Evolution of Fire-Resistant Textiles by R. W. Little in the Proceedings of the American Association of Textile Chemists and Colorists, 37, lid-11 8 at page 116 (1948) wherein it is stated:

The mechanisms discussed thus far have considered only prevention of the flaming of a fabric. It has been recognized recently that the phenomenon of afterglow is an entirely difierent reaction, independent of the afterfiaming tendency. Whereas there are innumerable compounds possessing flame-retarding properties, there are very few glowproofing agents and only two theories of their method of operation.

I have now discovered that fiame-, as well as glow-, retardant effects may be imparted to combustible materials such as cellulosic products by the application thereto of a mixture of antimony and titanium compounds, together with the water-soluble, alkaline-reacting, nitrogenand phosphorus-containing condensation product derived by the reaction of phosphorus oxychloride with anhydrous ammonia.

Examples of antimony and titanium compounds employed are the oxides derived by the hydrolysis of water-soluble salts such, for example, as antimony trichloride, titanyl chloride, or the corresponding bromides, sulfates, etc., or mixtures thereof.

The relative proportions of each single metal compound present may be varied over a wide range depending upon the material treated. However, for best results when treating textile fabrics I prefer to employ proportions in which the antimony compound is present in amount ranging from equal molar proportions to as much as two moles thereof to one mole of titanium salt.

The water-soluble, nitrogenand phosphoruscontaining product is described in copending application Serial No. 169,513, filed June 21, 1950, which application is assigned to the same assignee as is the present case. This combination results in the production of a permanent flameretardant product of excellent hand, which exhibits substantially the strength of the untreated fabric.

According to the copending application referred to above, the nitrogenand phosphoruscontaining products utilized in the present invention are produced by reacting together phosphorus oxychloride and ammonia, preferably in an inert solvent at a temperature below 100 C. The product produced by this reaction is then heated to a temperature of at least 110 C., but not above 150 C. The above reaction results in the formation of by-product ammonium chloride corresponding in amount to the chlorine present in the phosphorus oxychloride. For the present purpose the ammonium chloride should be largely removed. This is done by the extraction of the heat-treated phosphorus oxychlorideammonia reaction product by means of solvents. In general, the extraction is best carried out by employing liquid anhydrous ammonia as the extracting solvent, which dissolves the ammonium chloride preferentially leaving the nitrogenphosphorus compound as a white, non-hygroscopic solid.

In carrying out the process of the invention to produce the present products, the preparation may suitably commence with the solution of phosphorus oxychloride in a solvent. The phosphorus oxychloride so dissolved is then reacted with ammonia in gaseous or liquid form with suitable agitation. The temperature should be maintained below 100 C. during the addition of the ammonia. However, after the addition of at least the stoichiometric proportion of ammonia moles per mole of POCla) the temperature is raised and the product heated to at least 110 0., but not above 150 C. It has been found that the temperature control within the above limits is essential to prevent the formation of a waterinsoluble product on the one hand, and on the other hand to alter the intermediate product so that the subsequent separation and purification steps can be carried out successfully. The reaction of phosphorus oxychloride with ammonia, followed by heating the reaction product to at least 110 C., but not above 150 0., yields the desired composition in a form insoluble in liquid anhydrous ammonia. Ammonium chloride is formed as a by-product by reaction of ammonia with the chlorine present in the phosphorus oxychloride. As a result of the conditions under which the present product is prepared, it has been found to be possible to form the nitrogenphosphorus product so that it possesses solubility characteristics enabling the subsequent separation of the product from the ammonium chloride to be carried out by differential solubility methods. At the same time the desired product is obtained in a form which is highly reactive with cellulose.

Preferred solvents for carrying out the production of the initial condensation product of ammonia with phosphorus oxychloride are any inert liquid, such as kerosene, naphtha, hexane, benzene, acetone, or other organic liquids which do not react with ammonia or phosphorus oxychloride.

Phosphorus oxychloride to the amount Of 93 pounds is dissolved in gallons of hexane contained in an autoclave. The solution is heated to approximately 55 C. while stirring, and gas eous anhydrous ammonia is added thereto. Al though an exothermic reaction takes place, the reaction may be carried out at about 75 C. by cooling the vessel. Ammonia to the extent of 50 pounds (5 moles per mole of phosphorus oxychloride) is added to the autoclave over a two hour period. An excess of ammonia may be used. After the addition of this amount of ammonia, the autoclave is sealed and then heated to about C. for approximately 1%.; hours. After the completion of the heating period, the reaction mixture is cooled to below 40 C. and then transferred to a second vessel containing a filter element and provided with external heating means. By applying heat to the autoclave contents the hexane present is distilled off, condensed and recovered. The remaining solids which consist of a mixture of the nitrogenand phosphorus-con taining product with ammonium chloride are then extracted under pressure with anhydrous ammonia at about room temperature. A total of about 20 pounds of ammonia per pound of final product is employed, although it is also possible to carry out an extraction with 10 pounds of ammonia per pound of product. The slurry of product in anhydrous liquid ammonia was filtered by means of a filtering device contained within the autoclave. In this manner, substantially all of the ammonium chloride is leached from the residual solids. After the last extraction the residual ammonia adhering to the product is removed by evaporation induced by the application of heat to the product. The yield of the nitrogen-phosphorus product ob tained is approximately 85% of the theoretical. The product contains 33.8% nitrogen, 35.1% phosphorus, N/P ratio:2.l4. This is an atomic ratio.

The nitrogen-phosphorus product so produced has, when dissolved in aqueous solutions, a pH within the range of from 7.0 to 8.5, molecular weight of from to 300, a preferred range being from 200 to 250, a nitrogen to phosphorus atomic ratio of from 2.1 to 2.3, the latter ratio depending somewhat upon the temperature employed in the heating step. The so-formed nitrogen-phosphorus product is soluble not only in water, but also in glycerine, ethylene glycol, and formamide.

Cellulosic textile products are impregnated or coated with the above-described nitrogen-phos phorus-containing product, either before or after the deposition of the antimony and titanium compounds, by immersing textile materials in solutions thereof. Aqueous solutions are pre ferred, but other solvents may also be used. The concentration of the solutions may vary over a wide range, depending upon the desired addon which is to be obtained. It is generally desirable for the present purpose to add from 5% to 30% of the mixture of antimony and titanium compounds together with at least 1% of the phosphorus-nitrogen-containing product to the textile fabric. A preferred range is from 1% to 5%, but higher concentrations such as 10% or 25% may be employed. In the treatment of rayon, by the present process, it has been found that dimensional stabilization is greatly improved as a result of the deposition of the nitrogen-phosphorus condensation product.

After impregnation of the textile fabric and in order to produce a wash-fast fabric, the impregnated fabric is dried and then subjected to a temperature of at least 100, but below 200 C. If it is not necessary to produce a wash-fast product the heating step may be omitted.

The application of the fire-retardant treatment of the present invention to such materials as tentage and other fabrics and fibrous sub subjected to rain and other water leaching effects a useful field for the combination treatment based upon the present invention, inasmuch as the material treated by the present process can withstand indefinite action by water without losing its effectiveness as a flame-retard ing and glow-retarding treatment.

The nitrogenwhosphorus-containing product and the in t re of antimony and titanium compounds may be applied to fabrics by a succession of treatments in which an initial padding or impregnation of the material with a water solution of the antimony and titanium compounds and neutralization thereof is followed by a further impregnation or padding with a solution of the nitrogen-phcsphorus-containing compound. The nitrogen-phosphorus compound may be ap plied from an aqueous solution, since it is an advantage of this material that it is soluble in water, although the cured material is insoluble and resists washing. The aqueous solution may conveniently contain 1% to by weight of the nitrogen-phosphorus compound. Such solutions readily achieve an add-on or deposition of at least 1%, preferably from 1% to 5% by weight based upon the weight of the base material or fabric. A preferred range of concentrations for use in the present combination treatment, to gether with the antimony-titanium flame-retardant is 1% to 5% add-on, calculated from the weight of the untreated base material. However, it may in some cases be desirable to apply higher concentrations.

Should a be desirable to impart additional creasewear resistant properties to textile products, the treatment thereof with the nitrogen phosphorus compound together with the antimony-titanium compounds may be supplemented by treatment with a water-soluble, condensation product, such as a water-soluble, ureaor melamine-formaldehyde product. Such water-soluble condensation products have the property of being heat-convertible; that is, they may be further condensed by the applicatlon of heat to form a water-insoluble condensation product. Such supplemental treatment gives improved products and also aids in the retention of the flame glowprcofiing constituents on the fabric.

The type of condensation products which may be employed are the water-soluble reaction products of aldehydes, such as formaldehyde or furfurai with urea or melamine. Condensation products of this type are dimethylol urea, or the di-, trior tetramethylol melamine. Such condensation products are broadly applicable so that their constitution is not critical in the present invention. Suitable water-soluble types of these condensation products are further described in R. L. Wakeman, Chemistry of Commercial Plastics, pages 11342 6 (Reinhold Publishing Co., 15347) and by Nauth, Chemistry and Technology of Plastics, chapter 3 (Reinhold Publishing Co, 19 17).

The order of application is not especially critialthough it has been found that when the antimony-titanium compounds are first applied to textiles, followed by the nitrogen-phosphoruscontaining condensation product, the wash fastness of the. textiles is. somewhat better than when the order is reversed.

If a ureaor melamine-aldehyde condensation product is employed it may be used in such con centrations as to give an add-on of from 1% to by weight of the dry fabric, generally a preferred range of from 3% to 10% by weight being sufiicient. The concentration of the aqueous solutions from which the ureaor melaminealdehyde condensation product is applied may be varied over the range of from 1% to 20% by weight.

The. invention is illustrated by the following examples. The samples of treated materials prepared in the following examples were subjected to the standard flame-resistance and afterglow determinations. The details of the testing procedure utilized in these determinations are described by R. W. Little in Flameproofing Fabric Materials (Reinhold Publishing Co., 1947, pages 111-115). The test data obtained are summarized in the table which immediately follows the examples.

EXAMPLE 1 A sample of treated textile product was prepared by immersing a swatch of cotton sheeting in a solution of antimony chloride and titanyl chloride, in which solution the above chlorides were present in approximately equimolal ratio. The solution contained approximately 450 g. per liter of these compounds calculated as the respective oxides and contained in addition suflicient hydrochloric acid to prevent hydrolysis of the chlorides. The cotton swatch was passed through the above solution and then squeezed between rollers until it retained approximately by weight of the impregnating solution. The material was allowed to remain damp in order to aid in further processing.

The damp fabric so obtained was next passed through a 15% sodium carbonate solution. The action of the sodium carbonate solution causes precipitation of insoluble compounds of antimony and titanium upon the textile fibers. The fabric was then washed with water and dried.

EXMPLE 2 A cotton swatch treated as described in Example 1 was further impregnated with a melamine-formaldehyde, water-soluble condensation product by immersion in a water-solution containing 3.5% of the said condensation prodnot. The add-on obtained was about 3%. The material was then heated at C. for 10 minutes in order to cure the resin. The sample was then subjected to the tests described above.

EXALEPLE 3 A sample of the untreated cotton sheeting was first impregnated with an aqueous solution of the melamine-formaldehyde condensation product and an addon comparable to that shown in Example 2 obtained. The cotton swatch was then treated with the antimony-titanium salt solution, and then in the sodium carbonate solution as described in Example 1. The swatch was then washed and dried.

EXAMPLE 4 A sample of the cotton cloth which was treated by the method of Example 1 and which contained mixed antimony and titanium oxides was passed through a 5% aqueous solution of the nitrogenphosphoruscontaining condensation product de scribed in application Serial No. 169,513, filed June 21, 1950. Approximately by weight of nitrogen phosphorus containing condensation product was applied to the fabric. The sample so obtained was heated at a temperature of 150 C. for minutes, after which the material was subjected to the standard tests. The sample which had been washed once showed an afterglow time of nine seconds.

In a modification of this example, the cotton swatch was first treated with a 5% aqueous solution of the nitrogen-phosphorus condensation product referred to above in order to achieve an add-on of about 5% by weight. The material was then passed through the antimony-titanium chloride bath and the sodium carbonate precipitation tank described in Example 1. The treated sample was then cured at 150 C. for 10 minutes, after which the sample was subjected to the standard tests. The sample which had been washed once showed an afterglow period of 13 seconds.

EXAMPLE 5 A cotton swatch was first treated with the mixed antimony-titanium chlorides followed by treatment with sodium carbonate, as described in Example 1 above, and then immersed in an aqueous solution containing 10% by weight of urea-formaldehyde condensation product and I was first immersed in an aqueous solution containing 10% by weight of a urea-formaldehyde condensation product and also containing 3% by weight of the nitrogen-phosphorus condensation product referred to in application Serial No. 169,513. passed through the mixed antimony and titanium chloride solution and precipitated by immersion in aqueous sodium carbonate, as described in Example 1 above. This material was then heated in order to further condense the urea-formaldehyde resin, then subjected to the washing tests, after which it was dried and then tested for flameand glow-resistance. The sample which had been washed once showed an after-glow period of 5 seconds.

Repetition of this example with a water-soluble, melamine-formaldehyde gave substantially similar results.

EXAMPLE 6 In view of the fact that silicic acid treatments have been suggested as glowproofing agents, a test was made in order to determine the effectof such silicic acid treatment upon the antimony-titanium oxide flameproofing treatment.

The treatments were applied to the cotton fabric utilized above. The silicic acid glowproofer was applied first by immersion of the fabric in a 10% aqueous solution of sodium silicate and an add-on of approximately 3% by weight of 5102. obtained. A second test was also made employing a sodium silicate solution containing only 3% of sodium silicate. The cloth samples were then passed through the aqueous solution of antimony and titanium chloride then through a caustic The so-treated product was then a soda solution and the material dried. An addon of approximately 18% was obtained. The samples were dried and tested.

In order to determine the degree of wash fastness imparted by the various treatments of the examples described above, all of the samples prepared as described in the above examples were subjected to a standard washing procedure, utilizing 0.5% solution of a synthetic detergent. The samples, after washing for 10 minutes at a temperature of F., were then rinsed at 120 F. One sample of fabric treated, as described in each of the examples above, was washed once, while another sample, similarly prepared, was washed five times. The so-washed samples were then examined for length of afterglow.

The results given in the table below illustrate the length of time during which glowing combustion persisted after extinguishment of the flame on the sample. The above time is reported in seconds, the tests, however, being discontinued when a sample continued to glow for more than 200 seconds.

Table Afterglow ix. Treatment I wash 5 washes l.. Antimony-titaniumn com- Over 200 sec". Ovcr200 scc.

pounds alone. 2.-.. Amimony-l-titauium com- (lo... Do.

pounds [all nvccl by molami ciormaldchydo prodnet. 3 Antiuiony+titauium com- .do Do.

pounds preceded by melamine-formaldehyde product. 4 .lntimony-l-titanium compounds followed by nitrogou-phosp horns condensation product. 5. Antimouy+tltanium compounds followed by ureaiormaldchydc condensation product+nitrogenphosphorus condensation product. 6. Antimony+titanium precoded by sodium silicate:

10% s0ll(ls....... 21 Burned over. 3% solids G0 200 sec.

The results in the above table summarize the glow periods in seconds during which the materials continued to glow after the extinguishment of the flame. It is readily apparent that the antimony and titanium compounds accelerate the development of afterglow, so that a fiameproofing treatment utilizing such compounds without further treatment is inadequate to suppress the propagation of a fire. It is also shown in the above table that the combination of the nitrogen-phosphorus compound together with the antimony and titanium compounds results in an improved process and a product which is adequately flame-retardant and glowresistant.

The above examples also show that the reduction of afterglow by treatment with the particular nitrogen-phosphorus compound may precede or follow the process of treating against afterflaming by the use of antimony chloride and titanyl chloride. This flexibility of processing is an advantage over such treatments as silicic acid illustrated above, since this material must be precipitated upon the fabric using the disadvantageous method of acid precipitation following the deposition of sodium silicate. When such process is employed with the acid solution of antimony chloride and titanyl chloride, as herein described, it is found that when adequately large proportions of silicic acid are precipitated, then the blanketing efiect of this compound upon the fibers prevents the addition of sufficiently large amounts of the antimony and titanium compounds to prevent afterfiaming. This is illustrated in the test data relative to Example 8, wherein the results are presented as to samples treated in sodium silicate baths.

The details of the treating process are not critical. Variables such as temperature, time and solution concentration may be maintained at convenient values to obtain any desired addon. Heavy fabrics require relatively low pro portions by weight compared to finer fibers and fabrics.

What I claim is:

of imparting flameand glowto cellulosic materials which acting said in terials with a r titanium chlorides and lizing the same by alkali to any and titanium oxides, and sep the said cellulosic mateef previously prepared rog l and phosphorus-containby reacting one mole of oride with at least five moles monia in inert solvent, which see not react with the said re- -perature below 100 0., to proformed, anhydrous-ammonia- 110 but below 150 0., until said 1 .l phosphorus-containing product is .dered substantially insoluble in liquid anye one an iionia, said reaction product having nolecuiar weight within the limits of from 18i1300, a nitrogen/phosphorus atomic ratio in the limits of from 2.1 to 2.3, and when saturated solution in water yielding a solution having a pH Within the limits of 7.0 to and tliereai r drying the said impregceilulosic material.

2. The method of imparting flameand glowretardant effects to cellulosic materials Which comprises impregnating said materials with a mixture of antimony and titanium chlorides and subsequently neutralizing the same by alkali to form antimony and titanium oxides, and separately impregnating the said cellulosic materials with at least 1% of previously prepared solution of a nitrogen and phosphorus-containing product obtained by reacting one mole of phosphorus oxychloride with at least five moles of anhydrous ammonia in an inert solvent, which dissolves but does not react with the said re actants, at a temperature below 100 0., to produoe an initially-formed, anhydrous-ammoniasoluble product mixed with ammonium chloride, then heating said initially-formed nitrogen and phosphorus-containing product to a temperature of at least 110 C., but below 150 C., until said nitrogen and phosphorus-containing product is rendered substantially insoluble in liquid anhydrous ammonia, and exhibits a pH within the range of 7.0 to 8.5 in aqueous solution, has a molecular weight of from 180 to 300 and a nitrogen/ phosphorus atomic ratio within the limits of 2.1 to 2.3, and thereafter drying the said impregnated cellulosic material.

3. The method of imparting fiameand glowretardant efiects to cellulosic material which comprises impregnating the said material with a solution of antimony chloride and titanyl chloride and subsequently neutralizing the same with alkali to form antimony and titanium 0xides, and separately impregnating the said cellulosic material with a previously prepared solution of a nitrogen and phosphorus-containing product having a molecular weight within the limits of from 180-300, a nitrogen/phosphorus atomic ratio within the limits of from 2.1 to 2.3, and when dissolved as a saturated solution in water yielding a solution having a pH within the limits of 7.0 to 8.5, and obtained by reacting one mole of phosphorus oxychloride with at least five moles of anhydrous ammonia in an inert solvent, which dissolves but does not react with the said reactants, at a temperature below C., to produce an initially-formed, anhydrousammonia-soluble product mixed with ammonium chloride, then heating said initially-formed nitrogen and phosphorus-containing product to a temperature of at least C., but below C., until said nitrogen and phosphorus-containing product is rendered substantially insoluble in liquid anhydrous ammonia, and separately contacting the said cellulosic material with an aqueous solution of a water-soluble urea-formaldehyde condensation product, and thereafter drying the said impregnated cellulosic material.

4. The method of imparting flameand glowretardant effects to cellulosic material which comprises impregnating said material with a solution of antimony chloride and titanyl chloride and subsequently neutralizing the same with alkali to form antimony and titanium oxides and separately impregnating the said cellulosic material with a previously prepared solution of a nitrogen and phosphorus-containing product having a molecular weight within the limits of from -800, a nitrogen/phosphorus atomic ratio Within the limits of from 2.1 to 2.3, and when dissolved as a saturated solution in water yielding a solution having a pH Within the limits of 7.0 to 8.5, and obtained by reacting one mole of phosphorus oxychloride with at least five moles of anhydrous ammonia in an inert solvent, which dissolves but does not react with the said reactants, at a temperature below 100 C., to produce an initially-formed, anhydrous-ammonia-soluble product mixed with ammonium chloride, then heating said initially-formed nitrogen and phosphorus-containing product to a temperature or at least 110 (3., but below 150 0., until said nitrogen and phosphorus-containing product is rendered substantially insoluble in liquid anhydrous ammonia, and separately contacting the said cellulosic material with an aqueous solution of a water-soluble melamineformaldehyde condensation product, and thereafter drying the said impregnated cellulosic material.

5. The method of imparting fiameand glowretardant efiects to cellulosic material which comprises impregnating the said material with a solution or" antimony chloride and titanyl chloride and subsequently neutralizing the same with alkali to form antimony and titanium oxides, and separately impregnating the said cellulosic material with a previously prepared solution of a nitrogen and phosphorus-containing product having a molecular weight within the limits of from 180-300, a nitrogen/phosphorus atomic ratio within the limits of from 2.1 to 2.3, and when dissolved as a saturated solution in water yielding a solution having a pH within the limits of 7.0 to 8.5, and obtained by reacting one mole of phosphorus oxychloride with at least five moles of anhydrous ammonia in an inert solvent, which dissolves but does not react with the said reactants, at a temperature below 100 C., to produce an initially-formed, anhydrous-ammoniasoluble product mixed with ammonium chloride, then heating said initially-formed nitrogen and phosphorus-containing product to a temperature of at least 110 C., but below 150 C., until said nitrogen and phosphorus-containing product is rendered substantially insoluble in liquid anhydrous ammonia, and separately contacting the said cellulosic material with an aqueous solution of a water-soluble condensation product selected from the group consisting of urea-formaldehyde, melamine-formaldehyde, urea-furfural and melamine-furfural condensation products, and thereafter drying the said impregnated cellulosic material.

6. Glowproofed and fiameproofed fabric comprising cellulosic material impregnated. with antimony and titanium oxides and a nitrogen and phosphorus-containing product having a molecular weight within the limits of from 180- 300, a nitrogen/phosphorus atomic ratio within the limits of from 2.1 to 2.3, and when dissolved as a saturated solution in water yielding a solution having a pH within the limits of 7.0 to 8.5, and obtained by reacting one mole of phosphorous oxychloride with at least five moles of ammonia in an inert solvent which dissolves but does'not react with the said reactants, at a temperature below 100 C., to produce an initially-formed, anhydrous-ammonia-soluble product mixed with ammonium chloride, then heating said initially- 7. Glowproofed and fiameproofed fabric comprising a cellulosic base material impregnated with antimony and titanium oxides and a watersoluble condensation product selected from the group consisting of urea-formaldehyde, melamine-formaldehyde, urea-furfural and melamine-furiural, and also a nitrogen and phosphorus-containing product having a molecular weight Within the limits of from 180-300, 2. nitrogen/phosphorus atomic ratio within the limits of from 2.1 to 2.3, and when dissolved as a saturated solution in water yielding a solution having a pH within the limits of 7.0 to 8.5, and which nitrogenand phosphorus-containing product is prepared by reacting one mole of phosphorus oxychloride with at least five moles of ammonia in an inert solvent which dissolves but does not react with the said reactants, at a temperature below 100 C., to produce an initially-formed, anhydrous-ammonia-so1uble product mixed with ammonium chloride, then heating said initiallyi'orined nitrogen and phosphorus-containing product to a temperature of at least 110 C., but below 150" C., until said nitrogen and phosphorus-containing product is rendered substantially insoluble in liquid anhydrous ammonia.

MORRIS L. NIELSEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,052,886 Leroy Sept. 1, 1936 2,401,440 Thomas et a1. June l, 1946 2,416,447 Laughlin et a1. Feb. 25, 1947 2,427,997 White Sept. 23, 1947 2,462,803 Campbell et a1. Feb. 22, 1249 2,464,342 Pollak et al. Mar. 15, 1949 

1. THE METHOD OF IMPARTING FLAME-AND GLOWRETARDANT EFFECTS TO CELLULOSIC MATERIALS WHICH COMPRISES IMPREGNATING SAID MATERIALS WITH A MIXTURE OF ANTIMONY AND TITANIUM CHLORIDES AND SUBSEQUENTLY NEUTRALIZING THE SAME BY ALKALI TO FORM ANTIMONY AND TITANIUM OXIDES, AND SEPARATELY IMPREGNATING THE SAID CELLULOSIC MATERIALS WITH AT LEAST 1% OF PREVIOUSLY PREPARED SOLUTION OF A NITROGEN AND PHOSPHOROUS-CONTAINING PRODUCT OBTAINED BY REACTING ONE MOLE OF PHOSPHORUS OXYCHLORIDE WITH AT LEAST FIVE MOLES OF ANHYDROUS AMMONIA IN AN INERT SOLVENT, WHICH DISSOLVES BUT DOES NOT REACT WITH THE SAID REACTANTS, AT A TEMPERATURE BELOW 100* C., TO PRODUCE AN INITIALLY-FORMED, ANHYDROUS-AMMONIASOLUBLE PRODUCT MIXED WITH AMMONIUM CHLORIDE, THEN HEATING SAID INITIALLY-FORMED NITROGEN AND PHOSPHORUS-CONTAINING PRODUCT TO A TEMPERATURE OF AT LEAST 110* C., BUT BELOW 150* C., UNTIL SAID NITROGEN AND PHOSPHORUS-CONTAINING PRODUCT IS RENDERED SUBSTANTIALLY INSOLUBLE IN LIQUID ANHYDROUS AMMONIA, SAID REACTION PRODUCT HAVING A MOLECULAR WEIGHT WITHIN THE LIMITS OF FROM 180-300, A NITROGEN/PHOSPHORUS ATOMIC RATIO WITHIN THE LIMITS OF FROM 2.1 TO 2.3, AND WHEN DISSOLVED AS A SATURATED SOLUTION IN WATER YIELDING A SOLUTION HAVING A PH WITHIN THE LIMITS OF 7.0 TO 8.5, AND THEREAFTER DRYING THE SAID IMPREGNATED CELLULOSIC MATERIAL.
 7. GLOWPROOFED AND FLAMEPROOFED FABRIC COMPRISING A CELLULOSIC BASE MATERIAL IMPREGNATED WITH ANTIMONY AND TITANIUM OXIDES AND A WATERSOLUBLE CONDENSATION PRODUCT SELECTED FROM THE GROUP CONSISTING OF UREA-FORMALDEHYDE, MELAMINE-FORMALDEHYDE, UREA-FURFURAL, AND MELAMINE-FURFURAL, AND ALSO A NITROGEN AND PHOSPHORUS-CONTAINING PRODUCT HAVING A MOLECULAR WEIGHT WITHIN THE LIMITS OF FROM 180-300, A NITROGEN/PHOSPHORUS ATOMIC RATIO WITHIN THE LIMITS OF FROM 2.1 TO 2.3, AND WHEN DISSOLVED AS A SATURATED SOLUTION IN WATER YIELDING A SOLUTION HAVING A PH WITHIN THE LIMITS OF 7.0 TO 8.5, AND WHICH NITROGEN- AND PHOSPHORUS-CONTAINING PRODUCT IS PREPARED BY REACTING ONE MOLE OF PHOSPHROUS OXYCHLORIDE WITH AT LEAST FIVE MOLES OF AMMONIA IN AN INERT SOLVENT WHICH DISSOLVES BUT DOES NOT REACT WITH THE SAID REACTANTS, AT A TEMPERATURE BELOW 100* C., TO PRODUCE AN INITIALLY-FORMED, ANHYDROUS-AMMONIA-SOLUBLE PRODUCT MIXED WITH AMMONIUM CHLORIDE, THEN HEATING SAID INITIALLYFORMED NITROGEN AND PHOSPHORUS-CONTAINING PRODUCT TO A TEMPERATURE OF AT LEAST 110* C., BUT BELOW 150* C., UNTIL SAID NITROGEN AND PHOSPHORUS-CONTAINING PRODUCT IS RENDERED SUBSTANTIALLY INSOLUBLE IN LIQUID ANHYDROUS AMMONIA. 